diff -r 000000000000 -r a61af66fc99e src/share/vm/oops/methodDataOop.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/oops/methodDataOop.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,1341 @@ +/* + * Copyright 2000-2007 Sun Microsystems, Inc. All Rights Reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +class BytecodeStream; + +// The MethodData object collects counts and other profile information +// during zeroth-tier (interpretive) and first-tier execution. +// The profile is used later by compilation heuristics. Some heuristics +// enable use of aggressive (or "heroic") optimizations. An aggressive +// optimization often has a down-side, a corner case that it handles +// poorly, but which is thought to be rare. The profile provides +// evidence of this rarity for a given method or even BCI. It allows +// the compiler to back out of the optimization at places where it +// has historically been a poor choice. Other heuristics try to use +// specific information gathered about types observed at a given site. +// +// All data in the profile is approximate. It is expected to be accurate +// on the whole, but the system expects occasional inaccuraces, due to +// counter overflow, multiprocessor races during data collection, space +// limitations, missing MDO blocks, etc. Bad or missing data will degrade +// optimization quality but will not affect correctness. Also, each MDO +// is marked with its birth-date ("creation_mileage") which can be used +// to assess the quality ("maturity") of its data. +// +// Short (<32-bit) counters are designed to overflow to a known "saturated" +// state. Also, certain recorded per-BCI events are given one-bit counters +// which overflow to a saturated state which applied to all counters at +// that BCI. In other words, there is a small lattice which approximates +// the ideal of an infinite-precision counter for each event at each BCI, +// and the lattice quickly "bottoms out" in a state where all counters +// are taken to be indefinitely large. +// +// The reader will find many data races in profile gathering code, starting +// with invocation counter incrementation. None of these races harm correct +// execution of the compiled code. + +// DataLayout +// +// Overlay for generic profiling data. +class DataLayout VALUE_OBJ_CLASS_SPEC { +private: + // Every data layout begins with a header. This header + // contains a tag, which is used to indicate the size/layout + // of the data, 4 bits of flags, which can be used in any way, + // 4 bits of trap history (none/one reason/many reasons), + // and a bci, which is used to tie this piece of data to a + // specific bci in the bytecodes. + union { + intptr_t _bits; + struct { + u1 _tag; + u1 _flags; + u2 _bci; + } _struct; + } _header; + + // The data layout has an arbitrary number of cells, each sized + // to accomodate a pointer or an integer. + intptr_t _cells[1]; + + // Some types of data layouts need a length field. + static bool needs_array_len(u1 tag); + +public: + enum { + counter_increment = 1 + }; + + enum { + cell_size = sizeof(intptr_t) + }; + + // Tag values + enum { + no_tag, + bit_data_tag, + counter_data_tag, + jump_data_tag, + receiver_type_data_tag, + virtual_call_data_tag, + ret_data_tag, + branch_data_tag, + multi_branch_data_tag + }; + + enum { + // The _struct._flags word is formatted as [trap_state:4 | flags:4]. + // The trap state breaks down further as [recompile:1 | reason:3]. + // This further breakdown is defined in deoptimization.cpp. + // See Deoptimization::trap_state_reason for an assert that + // trap_bits is big enough to hold reasons < Reason_RECORDED_LIMIT. + // + // The trap_state is collected only if ProfileTraps is true. + trap_bits = 1+3, // 3: enough to distinguish [0..Reason_RECORDED_LIMIT]. + trap_shift = BitsPerByte - trap_bits, + trap_mask = right_n_bits(trap_bits), + trap_mask_in_place = (trap_mask << trap_shift), + flag_limit = trap_shift, + flag_mask = right_n_bits(flag_limit), + first_flag = 0 + }; + + // Size computation + static int header_size_in_bytes() { + return cell_size; + } + static int header_size_in_cells() { + return 1; + } + + static int compute_size_in_bytes(int cell_count) { + return header_size_in_bytes() + cell_count * cell_size; + } + + // Initialization + void initialize(u1 tag, u2 bci, int cell_count); + + // Accessors + u1 tag() { + return _header._struct._tag; + } + + // Return a few bits of trap state. Range is [0..trap_mask]. + // The state tells if traps with zero, one, or many reasons have occurred. + // It also tells whether zero or many recompilations have occurred. + // The associated trap histogram in the MDO itself tells whether + // traps are common or not. If a BCI shows that a trap X has + // occurred, and the MDO shows N occurrences of X, we make the + // simplifying assumption that all N occurrences can be blamed + // on that BCI. + int trap_state() { + return ((_header._struct._flags >> trap_shift) & trap_mask); + } + + void set_trap_state(int new_state) { + assert(ProfileTraps, "used only under +ProfileTraps"); + uint old_flags = (_header._struct._flags & flag_mask); + _header._struct._flags = (new_state << trap_shift) | old_flags; + assert(trap_state() == new_state, "sanity"); + } + + u1 flags() { + return _header._struct._flags; + } + + u2 bci() { + return _header._struct._bci; + } + + void set_header(intptr_t value) { + _header._bits = value; + } + void release_set_header(intptr_t value) { + OrderAccess::release_store_ptr(&_header._bits, value); + } + intptr_t header() { + return _header._bits; + } + void set_cell_at(int index, intptr_t value) { + _cells[index] = value; + } + void release_set_cell_at(int index, intptr_t value) { + OrderAccess::release_store_ptr(&_cells[index], value); + } + intptr_t cell_at(int index) { + return _cells[index]; + } + intptr_t* adr_cell_at(int index) { + return &_cells[index]; + } + oop* adr_oop_at(int index) { + return (oop*)&(_cells[index]); + } + + void set_flag_at(int flag_number) { + assert(flag_number < flag_limit, "oob"); + _header._struct._flags |= (0x1 << flag_number); + } + bool flag_at(int flag_number) { + assert(flag_number < flag_limit, "oob"); + return (_header._struct._flags & (0x1 << flag_number)) != 0; + } + + // Low-level support for code generation. + static ByteSize header_offset() { + return byte_offset_of(DataLayout, _header); + } + static ByteSize tag_offset() { + return byte_offset_of(DataLayout, _header._struct._tag); + } + static ByteSize flags_offset() { + return byte_offset_of(DataLayout, _header._struct._flags); + } + static ByteSize bci_offset() { + return byte_offset_of(DataLayout, _header._struct._bci); + } + static ByteSize cell_offset(int index) { + return byte_offset_of(DataLayout, _cells[index]); + } + // Return a value which, when or-ed as a byte into _flags, sets the flag. + static int flag_number_to_byte_constant(int flag_number) { + assert(0 <= flag_number && flag_number < flag_limit, "oob"); + DataLayout temp; temp.set_header(0); + temp.set_flag_at(flag_number); + return temp._header._struct._flags; + } + // Return a value which, when or-ed as a word into _header, sets the flag. + static intptr_t flag_mask_to_header_mask(int byte_constant) { + DataLayout temp; temp.set_header(0); + temp._header._struct._flags = byte_constant; + return temp._header._bits; + } +}; + + +// ProfileData class hierarchy +class ProfileData; +class BitData; +class CounterData; +class ReceiverTypeData; +class VirtualCallData; +class RetData; +class JumpData; +class BranchData; +class ArrayData; +class MultiBranchData; + + +// ProfileData +// +// A ProfileData object is created to refer to a section of profiling +// data in a structured way. +class ProfileData : public ResourceObj { +private: +#ifndef PRODUCT + enum { + tab_width_one = 16, + tab_width_two = 36 + }; +#endif // !PRODUCT + + // This is a pointer to a section of profiling data. + DataLayout* _data; + +protected: + DataLayout* data() { return _data; } + + enum { + cell_size = DataLayout::cell_size + }; + +public: + // How many cells are in this? + virtual int cell_count() { + ShouldNotReachHere(); + return -1; + } + + // Return the size of this data. + int size_in_bytes() { + return DataLayout::compute_size_in_bytes(cell_count()); + } + +protected: + // Low-level accessors for underlying data + void set_intptr_at(int index, intptr_t value) { + assert(0 <= index && index < cell_count(), "oob"); + data()->set_cell_at(index, value); + } + void release_set_intptr_at(int index, intptr_t value) { + assert(0 <= index && index < cell_count(), "oob"); + data()->release_set_cell_at(index, value); + } + intptr_t intptr_at(int index) { + assert(0 <= index && index < cell_count(), "oob"); + return data()->cell_at(index); + } + void set_uint_at(int index, uint value) { + set_intptr_at(index, (intptr_t) value); + } + void release_set_uint_at(int index, uint value) { + release_set_intptr_at(index, (intptr_t) value); + } + uint uint_at(int index) { + return (uint)intptr_at(index); + } + void set_int_at(int index, int value) { + set_intptr_at(index, (intptr_t) value); + } + void release_set_int_at(int index, int value) { + release_set_intptr_at(index, (intptr_t) value); + } + int int_at(int index) { + return (int)intptr_at(index); + } + int int_at_unchecked(int index) { + return (int)data()->cell_at(index); + } + void set_oop_at(int index, oop value) { + set_intptr_at(index, (intptr_t) value); + } + oop oop_at(int index) { + return (oop)intptr_at(index); + } + oop* adr_oop_at(int index) { + assert(0 <= index && index < cell_count(), "oob"); + return data()->adr_oop_at(index); + } + + void set_flag_at(int flag_number) { + data()->set_flag_at(flag_number); + } + bool flag_at(int flag_number) { + return data()->flag_at(flag_number); + } + + // two convenient imports for use by subclasses: + static ByteSize cell_offset(int index) { + return DataLayout::cell_offset(index); + } + static int flag_number_to_byte_constant(int flag_number) { + return DataLayout::flag_number_to_byte_constant(flag_number); + } + + ProfileData(DataLayout* data) { + _data = data; + } + +public: + // Constructor for invalid ProfileData. + ProfileData(); + + u2 bci() { + return data()->bci(); + } + + address dp() { + return (address)_data; + } + + int trap_state() { + return data()->trap_state(); + } + void set_trap_state(int new_state) { + data()->set_trap_state(new_state); + } + + // Type checking + virtual bool is_BitData() { return false; } + virtual bool is_CounterData() { return false; } + virtual bool is_JumpData() { return false; } + virtual bool is_ReceiverTypeData(){ return false; } + virtual bool is_VirtualCallData() { return false; } + virtual bool is_RetData() { return false; } + virtual bool is_BranchData() { return false; } + virtual bool is_ArrayData() { return false; } + virtual bool is_MultiBranchData() { return false; } + + BitData* as_BitData() { + assert(is_BitData(), "wrong type"); + return is_BitData() ? (BitData*) this : NULL; + } + CounterData* as_CounterData() { + assert(is_CounterData(), "wrong type"); + return is_CounterData() ? (CounterData*) this : NULL; + } + JumpData* as_JumpData() { + assert(is_JumpData(), "wrong type"); + return is_JumpData() ? (JumpData*) this : NULL; + } + ReceiverTypeData* as_ReceiverTypeData() { + assert(is_ReceiverTypeData(), "wrong type"); + return is_ReceiverTypeData() ? (ReceiverTypeData*)this : NULL; + } + VirtualCallData* as_VirtualCallData() { + assert(is_VirtualCallData(), "wrong type"); + return is_VirtualCallData() ? (VirtualCallData*)this : NULL; + } + RetData* as_RetData() { + assert(is_RetData(), "wrong type"); + return is_RetData() ? (RetData*) this : NULL; + } + BranchData* as_BranchData() { + assert(is_BranchData(), "wrong type"); + return is_BranchData() ? (BranchData*) this : NULL; + } + ArrayData* as_ArrayData() { + assert(is_ArrayData(), "wrong type"); + return is_ArrayData() ? (ArrayData*) this : NULL; + } + MultiBranchData* as_MultiBranchData() { + assert(is_MultiBranchData(), "wrong type"); + return is_MultiBranchData() ? (MultiBranchData*)this : NULL; + } + + + // Subclass specific initialization + virtual void post_initialize(BytecodeStream* stream, methodDataOop mdo) {} + + // GC support + virtual void follow_contents() {} + virtual void oop_iterate(OopClosure* blk) {} + virtual void oop_iterate_m(OopClosure* blk, MemRegion mr) {} + virtual void adjust_pointers() {} + +#ifndef SERIALGC + // Parallel old support + virtual void follow_contents(ParCompactionManager* cm) {} + virtual void update_pointers() {} + virtual void update_pointers(HeapWord* beg_addr, HeapWord* end_addr) {} +#endif // SERIALGC + + // CI translation: ProfileData can represent both MethodDataOop data + // as well as CIMethodData data. This function is provided for translating + // an oop in a ProfileData to the ci equivalent. Generally speaking, + // most ProfileData don't require any translation, so we provide the null + // translation here, and the required translators are in the ci subclasses. + virtual void translate_from(ProfileData* data) {} + + virtual void print_data_on(outputStream* st) { + ShouldNotReachHere(); + } + +#ifndef PRODUCT + void print_shared(outputStream* st, const char* name); + void tab(outputStream* st); +#endif +}; + +// BitData +// +// A BitData holds a flag or two in its header. +class BitData : public ProfileData { +protected: + enum { + // null_seen: + // saw a null operand (cast/aastore/instanceof) + null_seen_flag = DataLayout::first_flag + 0 + }; + enum { bit_cell_count = 0 }; // no additional data fields needed. +public: + BitData(DataLayout* layout) : ProfileData(layout) { + } + + virtual bool is_BitData() { return true; } + + static int static_cell_count() { + return bit_cell_count; + } + + virtual int cell_count() { + return static_cell_count(); + } + + // Accessor + + // The null_seen flag bit is specially known to the interpreter. + // Consulting it allows the compiler to avoid setting up null_check traps. + bool null_seen() { return flag_at(null_seen_flag); } + void set_null_seen() { set_flag_at(null_seen_flag); } + + + // Code generation support + static int null_seen_byte_constant() { + return flag_number_to_byte_constant(null_seen_flag); + } + + static ByteSize bit_data_size() { + return cell_offset(bit_cell_count); + } + +#ifndef PRODUCT + void print_data_on(outputStream* st); +#endif +}; + +// CounterData +// +// A CounterData corresponds to a simple counter. +class CounterData : public BitData { +protected: + enum { + count_off, + counter_cell_count + }; +public: + CounterData(DataLayout* layout) : BitData(layout) {} + + virtual bool is_CounterData() { return true; } + + static int static_cell_count() { + return counter_cell_count; + } + + virtual int cell_count() { + return static_cell_count(); + } + + // Direct accessor + uint count() { + return uint_at(count_off); + } + + // Code generation support + static ByteSize count_offset() { + return cell_offset(count_off); + } + static ByteSize counter_data_size() { + return cell_offset(counter_cell_count); + } + +#ifndef PRODUCT + void print_data_on(outputStream* st); +#endif +}; + +// JumpData +// +// A JumpData is used to access profiling information for a direct +// branch. It is a counter, used for counting the number of branches, +// plus a data displacement, used for realigning the data pointer to +// the corresponding target bci. +class JumpData : public ProfileData { +protected: + enum { + taken_off_set, + displacement_off_set, + jump_cell_count + }; + + void set_displacement(int displacement) { + set_int_at(displacement_off_set, displacement); + } + +public: + JumpData(DataLayout* layout) : ProfileData(layout) { + assert(layout->tag() == DataLayout::jump_data_tag || + layout->tag() == DataLayout::branch_data_tag, "wrong type"); + } + + virtual bool is_JumpData() { return true; } + + static int static_cell_count() { + return jump_cell_count; + } + + virtual int cell_count() { + return static_cell_count(); + } + + // Direct accessor + uint taken() { + return uint_at(taken_off_set); + } + // Saturating counter + uint inc_taken() { + uint cnt = taken() + 1; + // Did we wrap? Will compiler screw us?? + if (cnt == 0) cnt--; + set_uint_at(taken_off_set, cnt); + return cnt; + } + + int displacement() { + return int_at(displacement_off_set); + } + + // Code generation support + static ByteSize taken_offset() { + return cell_offset(taken_off_set); + } + + static ByteSize displacement_offset() { + return cell_offset(displacement_off_set); + } + + // Specific initialization. + void post_initialize(BytecodeStream* stream, methodDataOop mdo); + +#ifndef PRODUCT + void print_data_on(outputStream* st); +#endif +}; + +// ReceiverTypeData +// +// A ReceiverTypeData is used to access profiling information about a +// dynamic type check. It consists of a counter which counts the total times +// that the check is reached, and a series of (klassOop, count) pairs +// which are used to store a type profile for the receiver of the check. +class ReceiverTypeData : public CounterData { +protected: + enum { + receiver0_offset = counter_cell_count, + count0_offset, + receiver_type_row_cell_count = (count0_offset + 1) - receiver0_offset + }; + +public: + ReceiverTypeData(DataLayout* layout) : CounterData(layout) { + assert(layout->tag() == DataLayout::receiver_type_data_tag || + layout->tag() == DataLayout::virtual_call_data_tag, "wrong type"); + } + + virtual bool is_ReceiverTypeData() { return true; } + + static int static_cell_count() { + return counter_cell_count + (uint) TypeProfileWidth * receiver_type_row_cell_count; + } + + virtual int cell_count() { + return static_cell_count(); + } + + // Direct accessors + static uint row_limit() { + return TypeProfileWidth; + } + static int receiver_cell_index(uint row) { + return receiver0_offset + row * receiver_type_row_cell_count; + } + static int receiver_count_cell_index(uint row) { + return count0_offset + row * receiver_type_row_cell_count; + } + + // Get the receiver at row. The 'unchecked' version is needed by parallel old + // gc; it does not assert the receiver is a klass. During compaction of the + // perm gen, the klass may already have moved, so the is_klass() predicate + // would fail. The 'normal' version should be used whenever possible. + klassOop receiver_unchecked(uint row) { + assert(row < row_limit(), "oob"); + oop recv = oop_at(receiver_cell_index(row)); + return (klassOop)recv; + } + + klassOop receiver(uint row) { + klassOop recv = receiver_unchecked(row); + assert(recv == NULL || ((oop)recv)->is_klass(), "wrong type"); + return recv; + } + + uint receiver_count(uint row) { + assert(row < row_limit(), "oob"); + return uint_at(receiver_count_cell_index(row)); + } + + // Code generation support + static ByteSize receiver_offset(uint row) { + return cell_offset(receiver_cell_index(row)); + } + static ByteSize receiver_count_offset(uint row) { + return cell_offset(receiver_count_cell_index(row)); + } + static ByteSize receiver_type_data_size() { + return cell_offset(static_cell_count()); + } + + // GC support + virtual void follow_contents(); + virtual void oop_iterate(OopClosure* blk); + virtual void oop_iterate_m(OopClosure* blk, MemRegion mr); + virtual void adjust_pointers(); + +#ifndef SERIALGC + // Parallel old support + virtual void follow_contents(ParCompactionManager* cm); + virtual void update_pointers(); + virtual void update_pointers(HeapWord* beg_addr, HeapWord* end_addr); +#endif // SERIALGC + + oop* adr_receiver(uint row) { + return adr_oop_at(receiver_cell_index(row)); + } + +#ifndef PRODUCT + void print_receiver_data_on(outputStream* st); + void print_data_on(outputStream* st); +#endif +}; + +// VirtualCallData +// +// A VirtualCallData is used to access profiling information about a +// virtual call. For now, it has nothing more than a ReceiverTypeData. +class VirtualCallData : public ReceiverTypeData { +public: + VirtualCallData(DataLayout* layout) : ReceiverTypeData(layout) { + assert(layout->tag() == DataLayout::virtual_call_data_tag, "wrong type"); + } + + virtual bool is_VirtualCallData() { return true; } + + static int static_cell_count() { + // At this point we could add more profile state, e.g., for arguments. + // But for now it's the same size as the base record type. + return ReceiverTypeData::static_cell_count(); + } + + virtual int cell_count() { + return static_cell_count(); + } + + // Direct accessors + static ByteSize virtual_call_data_size() { + return cell_offset(static_cell_count()); + } + +#ifndef PRODUCT + void print_data_on(outputStream* st); +#endif +}; + +// RetData +// +// A RetData is used to access profiling information for a ret bytecode. +// It is composed of a count of the number of times that the ret has +// been executed, followed by a series of triples of the form +// (bci, count, di) which count the number of times that some bci was the +// target of the ret and cache a corresponding data displacement. +class RetData : public CounterData { +protected: + enum { + bci0_offset = counter_cell_count, + count0_offset, + displacement0_offset, + ret_row_cell_count = (displacement0_offset + 1) - bci0_offset + }; + + void set_bci(uint row, int bci) { + assert((uint)row < row_limit(), "oob"); + set_int_at(bci0_offset + row * ret_row_cell_count, bci); + } + void release_set_bci(uint row, int bci) { + assert((uint)row < row_limit(), "oob"); + // 'release' when setting the bci acts as a valid flag for other + // threads wrt bci_count and bci_displacement. + release_set_int_at(bci0_offset + row * ret_row_cell_count, bci); + } + void set_bci_count(uint row, uint count) { + assert((uint)row < row_limit(), "oob"); + set_uint_at(count0_offset + row * ret_row_cell_count, count); + } + void set_bci_displacement(uint row, int disp) { + set_int_at(displacement0_offset + row * ret_row_cell_count, disp); + } + +public: + RetData(DataLayout* layout) : CounterData(layout) { + assert(layout->tag() == DataLayout::ret_data_tag, "wrong type"); + } + + virtual bool is_RetData() { return true; } + + enum { + no_bci = -1 // value of bci when bci1/2 are not in use. + }; + + static int static_cell_count() { + return counter_cell_count + (uint) BciProfileWidth * ret_row_cell_count; + } + + virtual int cell_count() { + return static_cell_count(); + } + + static uint row_limit() { + return BciProfileWidth; + } + static int bci_cell_index(uint row) { + return bci0_offset + row * ret_row_cell_count; + } + static int bci_count_cell_index(uint row) { + return count0_offset + row * ret_row_cell_count; + } + static int bci_displacement_cell_index(uint row) { + return displacement0_offset + row * ret_row_cell_count; + } + + // Direct accessors + int bci(uint row) { + return int_at(bci_cell_index(row)); + } + uint bci_count(uint row) { + return uint_at(bci_count_cell_index(row)); + } + int bci_displacement(uint row) { + return int_at(bci_displacement_cell_index(row)); + } + + // Interpreter Runtime support + address fixup_ret(int return_bci, methodDataHandle mdo); + + // Code generation support + static ByteSize bci_offset(uint row) { + return cell_offset(bci_cell_index(row)); + } + static ByteSize bci_count_offset(uint row) { + return cell_offset(bci_count_cell_index(row)); + } + static ByteSize bci_displacement_offset(uint row) { + return cell_offset(bci_displacement_cell_index(row)); + } + + // Specific initialization. + void post_initialize(BytecodeStream* stream, methodDataOop mdo); + +#ifndef PRODUCT + void print_data_on(outputStream* st); +#endif +}; + +// BranchData +// +// A BranchData is used to access profiling data for a two-way branch. +// It consists of taken and not_taken counts as well as a data displacement +// for the taken case. +class BranchData : public JumpData { +protected: + enum { + not_taken_off_set = jump_cell_count, + branch_cell_count + }; + + void set_displacement(int displacement) { + set_int_at(displacement_off_set, displacement); + } + +public: + BranchData(DataLayout* layout) : JumpData(layout) { + assert(layout->tag() == DataLayout::branch_data_tag, "wrong type"); + } + + virtual bool is_BranchData() { return true; } + + static int static_cell_count() { + return branch_cell_count; + } + + virtual int cell_count() { + return static_cell_count(); + } + + // Direct accessor + uint not_taken() { + return uint_at(not_taken_off_set); + } + + uint inc_not_taken() { + uint cnt = not_taken() + 1; + // Did we wrap? Will compiler screw us?? + if (cnt == 0) cnt--; + set_uint_at(not_taken_off_set, cnt); + return cnt; + } + + // Code generation support + static ByteSize not_taken_offset() { + return cell_offset(not_taken_off_set); + } + static ByteSize branch_data_size() { + return cell_offset(branch_cell_count); + } + + // Specific initialization. + void post_initialize(BytecodeStream* stream, methodDataOop mdo); + +#ifndef PRODUCT + void print_data_on(outputStream* st); +#endif +}; + +// ArrayData +// +// A ArrayData is a base class for accessing profiling data which does +// not have a statically known size. It consists of an array length +// and an array start. +class ArrayData : public ProfileData { +protected: + friend class DataLayout; + + enum { + array_len_off_set, + array_start_off_set + }; + + uint array_uint_at(int index) { + int aindex = index + array_start_off_set; + return uint_at(aindex); + } + int array_int_at(int index) { + int aindex = index + array_start_off_set; + return int_at(aindex); + } + oop array_oop_at(int index) { + int aindex = index + array_start_off_set; + return oop_at(aindex); + } + void array_set_int_at(int index, int value) { + int aindex = index + array_start_off_set; + set_int_at(aindex, value); + } + + // Code generation support for subclasses. + static ByteSize array_element_offset(int index) { + return cell_offset(array_start_off_set + index); + } + +public: + ArrayData(DataLayout* layout) : ProfileData(layout) {} + + virtual bool is_ArrayData() { return true; } + + static int static_cell_count() { + return -1; + } + + int array_len() { + return int_at_unchecked(array_len_off_set); + } + + virtual int cell_count() { + return array_len() + 1; + } + + // Code generation support + static ByteSize array_len_offset() { + return cell_offset(array_len_off_set); + } + static ByteSize array_start_offset() { + return cell_offset(array_start_off_set); + } +}; + +// MultiBranchData +// +// A MultiBranchData is used to access profiling information for +// a multi-way branch (*switch bytecodes). It consists of a series +// of (count, displacement) pairs, which count the number of times each +// case was taken and specify the data displacment for each branch target. +class MultiBranchData : public ArrayData { +protected: + enum { + default_count_off_set, + default_disaplacement_off_set, + case_array_start + }; + enum { + relative_count_off_set, + relative_displacement_off_set, + per_case_cell_count + }; + + void set_default_displacement(int displacement) { + array_set_int_at(default_disaplacement_off_set, displacement); + } + void set_displacement_at(int index, int displacement) { + array_set_int_at(case_array_start + + index * per_case_cell_count + + relative_displacement_off_set, + displacement); + } + +public: + MultiBranchData(DataLayout* layout) : ArrayData(layout) { + assert(layout->tag() == DataLayout::multi_branch_data_tag, "wrong type"); + } + + virtual bool is_MultiBranchData() { return true; } + + static int compute_cell_count(BytecodeStream* stream); + + int number_of_cases() { + int alen = array_len() - 2; // get rid of default case here. + assert(alen % per_case_cell_count == 0, "must be even"); + return (alen / per_case_cell_count); + } + + uint default_count() { + return array_uint_at(default_count_off_set); + } + int default_displacement() { + return array_int_at(default_disaplacement_off_set); + } + + uint count_at(int index) { + return array_uint_at(case_array_start + + index * per_case_cell_count + + relative_count_off_set); + } + int displacement_at(int index) { + return array_int_at(case_array_start + + index * per_case_cell_count + + relative_displacement_off_set); + } + + // Code generation support + static ByteSize default_count_offset() { + return array_element_offset(default_count_off_set); + } + static ByteSize default_displacement_offset() { + return array_element_offset(default_disaplacement_off_set); + } + static ByteSize case_count_offset(int index) { + return case_array_offset() + + (per_case_size() * index) + + relative_count_offset(); + } + static ByteSize case_array_offset() { + return array_element_offset(case_array_start); + } + static ByteSize per_case_size() { + return in_ByteSize(per_case_cell_count) * cell_size; + } + static ByteSize relative_count_offset() { + return in_ByteSize(relative_count_off_set) * cell_size; + } + static ByteSize relative_displacement_offset() { + return in_ByteSize(relative_displacement_off_set) * cell_size; + } + + // Specific initialization. + void post_initialize(BytecodeStream* stream, methodDataOop mdo); + +#ifndef PRODUCT + void print_data_on(outputStream* st); +#endif +}; + +// methodDataOop +// +// A methodDataOop holds information which has been collected about +// a method. Its layout looks like this: +// +// ----------------------------- +// | header | +// | klass | +// ----------------------------- +// | method | +// | size of the methodDataOop | +// ----------------------------- +// | Data entries... | +// | (variable size) | +// | | +// . . +// . . +// . . +// | | +// ----------------------------- +// +// The data entry area is a heterogeneous array of DataLayouts. Each +// DataLayout in the array corresponds to a specific bytecode in the +// method. The entries in the array are sorted by the corresponding +// bytecode. Access to the data is via resource-allocated ProfileData, +// which point to the underlying blocks of DataLayout structures. +// +// During interpretation, if profiling in enabled, the interpreter +// maintains a method data pointer (mdp), which points at the entry +// in the array corresponding to the current bci. In the course of +// intepretation, when a bytecode is encountered that has profile data +// associated with it, the entry pointed to by mdp is updated, then the +// mdp is adjusted to point to the next appropriate DataLayout. If mdp +// is NULL to begin with, the interpreter assumes that the current method +// is not (yet) being profiled. +// +// In methodDataOop parlance, "dp" is a "data pointer", the actual address +// of a DataLayout element. A "di" is a "data index", the offset in bytes +// from the base of the data entry array. A "displacement" is the byte offset +// in certain ProfileData objects that indicate the amount the mdp must be +// adjusted in the event of a change in control flow. +// + +class methodDataOopDesc : public oopDesc { + friend class VMStructs; +private: + friend class ProfileData; + + // Back pointer to the methodOop + methodOop _method; + + // Size of this oop in bytes + int _size; + + // Cached hint for bci_to_dp and bci_to_data + int _hint_di; + + // Whole-method sticky bits and flags +public: + enum { + _trap_hist_limit = 16, // decoupled from Deoptimization::Reason_LIMIT + _trap_hist_mask = max_jubyte, + _extra_data_count = 4 // extra DataLayout headers, for trap history + }; // Public flag values +private: + uint _nof_decompiles; // count of all nmethod removals + uint _nof_overflow_recompiles; // recompile count, excluding recomp. bits + uint _nof_overflow_traps; // trap count, excluding _trap_hist + union { + intptr_t _align; + u1 _array[_trap_hist_limit]; + } _trap_hist; + + // Support for interprocedural escape analysis, from Thomas Kotzmann. + intx _eflags; // flags on escape information + intx _arg_local; // bit set of non-escaping arguments + intx _arg_stack; // bit set of stack-allocatable arguments + intx _arg_returned; // bit set of returned arguments + + int _creation_mileage; // method mileage at MDO creation + + // Size of _data array in bytes. (Excludes header and extra_data fields.) + int _data_size; + + // Beginning of the data entries + intptr_t _data[1]; + + // Helper for size computation + static int compute_data_size(BytecodeStream* stream); + static int bytecode_cell_count(Bytecodes::Code code); + enum { no_profile_data = -1, variable_cell_count = -2 }; + + // Helper for initialization + DataLayout* data_layout_at(int data_index) { + assert(data_index % sizeof(intptr_t) == 0, "unaligned"); + return (DataLayout*) (((address)_data) + data_index); + } + + // Initialize an individual data segment. Returns the size of + // the segment in bytes. + int initialize_data(BytecodeStream* stream, int data_index); + + // Helper for data_at + DataLayout* limit_data_position() { + return (DataLayout*)((address)data_base() + _data_size); + } + bool out_of_bounds(int data_index) { + return data_index >= data_size(); + } + + // Give each of the data entries a chance to perform specific + // data initialization. + void post_initialize(BytecodeStream* stream); + + // hint accessors + int hint_di() const { return _hint_di; } + void set_hint_di(int di) { + assert(!out_of_bounds(di), "hint_di out of bounds"); + _hint_di = di; + } + ProfileData* data_before(int bci) { + // avoid SEGV on this edge case + if (data_size() == 0) + return NULL; + int hint = hint_di(); + if (data_layout_at(hint)->bci() <= bci) + return data_at(hint); + return first_data(); + } + + // What is the index of the first data entry? + int first_di() { return 0; } + + // Find or create an extra ProfileData: + ProfileData* bci_to_extra_data(int bci, bool create_if_missing); + +public: + static int header_size() { + return sizeof(methodDataOopDesc)/wordSize; + } + + // Compute the size of a methodDataOop before it is created. + static int compute_allocation_size_in_bytes(methodHandle method); + static int compute_allocation_size_in_words(methodHandle method); + static int compute_extra_data_count(int data_size, int empty_bc_count); + + // Determine if a given bytecode can have profile information. + static bool bytecode_has_profile(Bytecodes::Code code) { + return bytecode_cell_count(code) != no_profile_data; + } + + // Perform initialization of a new methodDataOop + void initialize(methodHandle method); + + // My size + int object_size_in_bytes() { return _size; } + int object_size() { + return align_object_size(align_size_up(_size, BytesPerWord)/BytesPerWord); + } + + int creation_mileage() const { return _creation_mileage; } + void set_creation_mileage(int x) { _creation_mileage = x; } + bool is_mature() const; // consult mileage and ProfileMaturityPercentage + static int mileage_of(methodOop m); + + // Support for interprocedural escape analysis, from Thomas Kotzmann. + enum EscapeFlag { + estimated = 1 << 0, + return_local = 1 << 1 + }; + + intx eflags() { return _eflags; } + intx arg_local() { return _arg_local; } + intx arg_stack() { return _arg_stack; } + intx arg_returned() { return _arg_returned; } + + void set_eflags(intx v) { _eflags = v; } + void set_arg_local(intx v) { _arg_local = v; } + void set_arg_stack(intx v) { _arg_stack = v; } + void set_arg_returned(intx v) { _arg_returned = v; } + + void clear_escape_info() { _eflags = _arg_local = _arg_stack = _arg_returned = 0; } + + // Location and size of data area + address data_base() const { + return (address) _data; + } + int data_size() { + return _data_size; + } + + // Accessors + methodOop method() { return _method; } + + // Get the data at an arbitrary (sort of) data index. + ProfileData* data_at(int data_index); + + // Walk through the data in order. + ProfileData* first_data() { return data_at(first_di()); } + ProfileData* next_data(ProfileData* current); + bool is_valid(ProfileData* current) { return current != NULL; } + + // Convert a dp (data pointer) to a di (data index). + int dp_to_di(address dp) { + return dp - ((address)_data); + } + + address di_to_dp(int di) { + return (address)data_layout_at(di); + } + + // bci to di/dp conversion. + address bci_to_dp(int bci); + int bci_to_di(int bci) { + return dp_to_di(bci_to_dp(bci)); + } + + // Get the data at an arbitrary bci, or NULL if there is none. + ProfileData* bci_to_data(int bci); + + // Same, but try to create an extra_data record if one is needed: + ProfileData* allocate_bci_to_data(int bci) { + ProfileData* data = bci_to_data(bci); + return (data != NULL) ? data : bci_to_extra_data(bci, true); + } + + // Add a handful of extra data records, for trap tracking. + DataLayout* extra_data_base() { return limit_data_position(); } + DataLayout* extra_data_limit() { return (DataLayout*)((address)this + object_size_in_bytes()); } + int extra_data_size() { return (address)extra_data_limit() + - (address)extra_data_base(); } + static DataLayout* next_extra(DataLayout* dp) { return (DataLayout*)((address)dp + in_bytes(DataLayout::cell_offset(0))); } + + // Return (uint)-1 for overflow. + uint trap_count(int reason) const { + assert((uint)reason < _trap_hist_limit, "oob"); + return (int)((_trap_hist._array[reason]+1) & _trap_hist_mask) - 1; + } + // For loops: + static uint trap_reason_limit() { return _trap_hist_limit; } + static uint trap_count_limit() { return _trap_hist_mask; } + uint inc_trap_count(int reason) { + // Count another trap, anywhere in this method. + assert(reason >= 0, "must be single trap"); + if ((uint)reason < _trap_hist_limit) { + uint cnt1 = 1 + _trap_hist._array[reason]; + if ((cnt1 & _trap_hist_mask) != 0) { // if no counter overflow... + _trap_hist._array[reason] = cnt1; + return cnt1; + } else { + return _trap_hist_mask + (++_nof_overflow_traps); + } + } else { + // Could not represent the count in the histogram. + return (++_nof_overflow_traps); + } + } + + uint overflow_trap_count() const { + return _nof_overflow_traps; + } + uint overflow_recompile_count() const { + return _nof_overflow_recompiles; + } + void inc_overflow_recompile_count() { + _nof_overflow_recompiles += 1; + } + uint decompile_count() const { + return _nof_decompiles; + } + void inc_decompile_count() { + _nof_decompiles += 1; + } + + // Support for code generation + static ByteSize data_offset() { + return byte_offset_of(methodDataOopDesc, _data[0]); + } + + // GC support + oop* adr_method() const { return (oop*)&_method; } + bool object_is_parsable() const { return _size != 0; } + void set_object_is_parsable(int object_size_in_bytes) { _size = object_size_in_bytes; } + +#ifndef PRODUCT + // printing support for method data + void print_data_on(outputStream* st); +#endif + + // verification + void verify_data_on(outputStream* st); +};